This invention relates, generally, to receptacles or containers with one-way openings for receiving blood collection needles contaminated with the blood of patients. More particularly, this invention relates to a cap which may be used with a variety of such receptacles which accommodate the user of blood collection needles by allowing for a wrenching action for gripping the hub of the needle so that the needle may be unscrewed from the rest of the collection device and subsequently thrust through the opening of the cap to be disposed of in the associated container. With such an arrangement, users of blood collection needles do not come in contact with any of the needle surface, they are not accidentally punctured by the needles and they do not need to, for any reason, touch the needles or their hubs.
In the last several years, medical practitioners and paramedical technicians have become increasingly aware of the danger of contamination to themselves in the handling of blood collection needles, once a blood specimen has been taken from a patient who may be suffering from some contagious disease. Recently, such dangers have been intensified by the publicity engenered by the rapid increase in the spread of the Acquired Immune Deficiency Syndrome (AIDS) Virus. For that one disease alone, it is extremely important that no blood contact be made between the medical technician or practitioner's blood, and the blood of a diseased patient.
A further problem arises later, of course, after the technician or practitioner has disposed successfully of the contaminated needle without being contaminated by the needle. That is, if such needles are simply discarded in the trash of a hospital or clinic, for example, anyone handling the garbage in the long succession of the passage of the garbage from the institution to a garbage dump may be exposed to contamination by those needles simply by someone grasping a bag containing such needles and puncturing their finger, for example. Moreover, such needles may be laid aside by a physician or technician during a difficult procedure, without thinking, and someone might lean against a table or shelf where the contaminated needle is lying and contaminate their own blood with a blood sample from the needle.
While awareness of the contamination problem has increased considerably in the last two or three years, the danger of contamination has been around for a long time and a wide assortment of devices have been provided through the years to make disposal techniques safe and fast. Some devices, for example, have been developed to receive contaminated needles through an opening in the top of a container which cannot be opened. That is, the opening is surrounded by a plurality of integral flaps which are flexible and allow receipt of a sharp object through the opening. However, no one can remove the sharp objects passing through the opening in the opposite direction. This arrangement is satisfactory, providing that the needle does not have to be removed from the rest of the collection device. However, such an arrangement does not allow removal of the contaminated needle from a holder so that the holder itself may be utilized for subsequent blood collections. It follows that manual separation is required which invites contamination. Representative of such devices are containers such as those described and claimed in U.S. Pat. Nos. 4,520,926 and 4,454,944. Both of these patents include arrangements for receiving not only single and multiple sample blood collection needles, but also syringes including the entire body of the syringe.
A further arrangement of blood collection needle receiving containers for contaminated needles is taught in U.S. Pat. No. 4,466,538. The arrangement in that patent not only provides a one-way opening for receiving contaminated needles, but also, the opening includes a tapered configuration. The point of the tapered walls of the opening is to allow a large opening at one end to receive the hub of a needle. Thus, the user may move the needle hub in the opening from the large end of the opening to a more narrow portion of the opening in order to provide a wedging action so that the user may unscrew the needle hub from the rest of the blood collection assembly. Subsequent to the unscrewing manipulation, the released needle and hub are moved back toward the larger portion of the opening so the needle and hub will pass through the opening into the container below.
Difficulties have taken place in the use of such arrangements, however, in that the needle hubs have a tendency to become "hung-up" in the narrow portion of the opening so that the user must manually unwedge and move the needle hub from the narrow portion of the opening to the wider portion so that the needle and hub will drop in. This, of course, creates the danger that the technician may become contaminated with blood on the contaminated needle during this maneuver to attempt to remove the needle hub from its wedged position in the opening.
This patent also includes the provision of the top surface of the cap having a slanted top surface so as to encourage the movement of the needle hub, once it has been unscrewed from the blood collection assembly to move downwardly toward the enlarged portion of the opening in the slanted surface of the cap of the container. Nevertheless, even with the downward slant of the opening, needle hubs become wedged readily in the narrow portion during the unscrewing or wrenching action necessary or required to unscrew the needle hub from the opening.
In U.S. Pat. No. 4,375,849 a collection cup of the kind discussed herein is designed to include a cap having a specially shaped opening for bearing engagement by the cartridge structure of a double ended needle unit to permit unthreading of the needle unit from a syringe barrel as a one-handed operation, whereupon the thus-separated needle unit is intended to fall into the collection cup without direct handling by the technician. However, such cap constructions have not prevented occasional jamming of the needle unit, as discussed above with respect to U.S. Pat. No. 4,466,538 such that it becomes necessary to dislodge the needle unit manually resulting in possible contamination or injury. Other collection cup designs have included a movable cap which can be closed when the cup is full to permit cup handling for disposal purposes without contacting the used needles. However, cap constructions of this type have been susceptible to relatively easy reopening, sometimes inadvertently, resulting in potential contamination, injury, or unauthorized reuse.
With this invention, by contrast, a cap or closure is provided for incorporation into a contaminated blood collection needle assembly with the surface thereof comprised of a thin flexible material which gives upon contact or receipt of a needle assembly through the opening disposed in the cap or closure. The arrangement of the invention here includes a specific configuration of opening having tapered walls in the manner discussed above with respect to the prior art. However, incorporated with the opening are a plurality of elongated slots extending from each side of the opening which provide a flexible wrenching action for the hub of a needle assembly thrust into the opening. That is, the flexible material of the cap "gives" with such a thrusting movement and then grips the hub and provides a wrenching action allowing the technician to unscrew the hub from the rest of the blood collection assembly.
Once this unscrewing action has taken place, the wrenching action is overcome simply by a further thrusting forward of the hub through the opening because of the built-in flexibility of the edges of the opening, in accordance with this invention. The tapered opening of the invention is such, that, alternatively, the unscrewed hub of the needle assembly may simply be moved toward the enlarged end of the opening for it to fall through the opening. At any rate, the flexibility of the engaging surfaces of the opening in combination with the elongated slots placed in strategic locations along each side edge thereof provides the appropriate gripping action for the hub for obtaining the unscrewing action required to release the hub from the rest of the collection assembly while still not causing the hub to be "hung-up" and wedged into the opening as was the case with the previous arrangements with rigid edges for the opening.
As a further feature of the invention herein, the specific combination of opening in the cap of the invention may be placed in a cap surface which is horizontal, or perpendicular to the axis of the cap. However, the top surface of the invention here may be inclined in the same manner as taught in the prior art patents discussed above but in the reverse direction, the incline downwardly being toward the small end of the opening. Such a slanted surface enhances the movement of the holder toward the wedging position for increasing the wrenching action to unscrew the hub from the rest of the assembly.
As purely illustrative of materials which may be used to form the flexible closure of the invention, one may select, for example, polypropylene. Another representative thermoplastic material is acrylonitrile-butadiene-styrene terpolymer. Furthermore, a thin flexible metallic cap may be utilized. The cap or closure of the invention, if it is made of a thermoplastic material, may be stamped, vacuum formed or injection molded. Preferably, the material will be polypropylene formed to have the major surface of the cap of a thickness of 1.27 mm. The range of thickness of the surface of the cap of the invention may be within the range of between about 0.1 and 2.0 mm. The dimension of the opening will be discussed in more detail below in the description of the drawings herein. However, it should be noted that the dimension of the opening is sized to accommodate any of the conventional needles on the market, such as those of Terumo, Sherwood and Becton, Dickinson and Company.